Obstructive Sleep Apnea (OSA) is a frequent condition affecting up to 3% of all pre-pubertal children and has now been recognized as imposing substantial physiological, neurological, and cognitive consequences (1-3). Indeed, if left untreated, OSA can lead to serious neurobehavioral and cardiovascular consequences. Among the first, daytime sleepiness, irritability, depression, attention deficit hyperactivity disorder (ADHD)-like behaviors, and poor cognitive function have all been reported in children suffering from OSA. In this regard, it has also been reported that OSA in children strongly and dose-dependently correlates with emotional problems, impaired school performance, hyperactivity, and aggressive and withdrawal behaviors. With respect to the cardiovascular consequences, untreated OSA been linked to hypertension, increased risk of myocardial infarction, and stroke. Furthermore, severe and longstanding cases of OSA have been associated with pulmonary hypertension and, in some cases, sudden unexpected death. Despite the seriousness of these consequences of OSA, however, it has been shown that some of these adverse consequences can be reversed if the OSA is diagnosed and treated early.
In the clinical setting, history and physical examination have extremely poor predictive value in differentiating between primary snoring (PS) and OSA (12-15). As such, current diagnostic approaches for OSA require an overnight sleep study or polysomnography (PSG) in a sleep laboratory, which is both costly and inconvenient, as well as labor intensive. Furthermore, due to the relative unavailability of suitable sleep facilities, particularly, pediatric sleep facilities, long waiting periods and unnecessary delays in diagnosis and treatment are frequent. Accordingly, the development of non-invasive biomarkers capable of reliably distinguishing subjects with PS from those with OSA would greatly facilitate timely screening and diagnosis of OSA, especially in children, which is of great importance in ameliorating the overall outcome of OSA.